The mission of the NRG Oncology Statistics and Data Management Center (SDMC) is to provide all necessary expertise and personnel for the design, conduct and analysis of clinical trials and associated research for NRG Oncology, a member group of the NCI National Clinical Trials Network (NCTN) program. The Statistics Core of the SDMC provides statistical methodology expertise for the conduct of cancer clinical trials and associated research. The Statistics Core is an integral component central to the SDMC and to NRG Oncology as a whole. Statisticians represent the most closely collaborating group within the SDMC with NRG Oncology investigators across the disease sites that the group addresses. In the first cycle (2014-2019) of the NCTN, the NRG Oncology SDMC was successfully formed from existent centers with specific areas of expertise, both in the disease sites and the attendant trial methodology. The SDMC has retained this expertise, but also broadened individuals? roles so that statisticians may engage in new disease sites, trial methodology, and analytic methods. This unification and expansion has strengthened the statistics group. During the first cycle, the statistics group enjoyed a highly productive period, supporting the initiation of 32 new trials and obtaining final approval on an additional 14 trials now in development, while continuing to maintain accrual and/or follow-up to primary and secondary endpoint reporting on over 80 additional trials that were active at the inception of NRG Oncology. With respect to contributions to the total NCTN effort, the accruing NRG Oncology trials during 2014-2017 represent 34% of all accruing NCTN trials. Publications from the group in the first cycle number over 300, including 39 statistics and clinical trials methodology articles by SDMC statisticians. In the second cycle of the NCTN, the Statistics Core will continue to carry out its critical trial conduct functions, beginning with trial design appropriate for the question, using innovative modern methods to develop efficient and maximally informative trials. Approaches such as integrated trial developmental phases and incorporation of modern biomarker-based information will be sought. Analysis plans for primary, secondary, and exploratory aims will reflect state-of-the-art statistical methodology, with novel methods developed as needed. The Statistics Core, working with other components of the SDMC, will provide continuous trial conduct oversight through all stages from concept and protocol development, trial monitoring, initial reporting, and publication. The statisticians will work closely with SDMC data management and information technology personnel to assure secure high-quality data collection, maintenance, and curation for additional discovery and data sharing.